Ice machine cooling capacity problem
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Due to the recent increase in ambient temperature, the -15°C system temperature has risen sharply, which has seriously affected production operations. Through observation and analysis of the operating status of the unit, the specific situation is as follows: No. Project Daleng 1# Daleng 2# Wu Leng Ice Machine 1# Wu Leng Ice Machine 2# Wu Leng Ice Machine 3# Smoke Cooling Total 1 System design demand cooling capacity/Kw75675614051405140521507877 2 Current equipment theoretical cooling capacity/kw/248.45 0.00 330.44 359.43 2060.94 2999.27 3 Refrigeration efficiency/0.33 0.00 0.24 0.26 0.96 5 Equipment water flow (rated)/m3/200280280280403 6 Equipment inlet and outlet water temperature difference/℃/1.2-0.961.141.244.94 Daleng is from Dalian Bingshan, Wuhan is from Wuhan New World Refrigeration, and Yanlen is from Yantai Binglun. appendix: Internal flow chart of Wuhan ice machine unit. file:///C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\ksohtml6100\wps1.jpg The flow chart of the entire system is as follows: file:///C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\ksohtml6100\wps2.jpg Regarding the calculation of the cooling capacity of the ice machine, Q=cm△T=PtC is used here as the specific heat of the refrigerant in the -15°C refrigeration system, 3.85J/Kg.℃m is taken as the mass per unit time, the density is taken as 0.968g/cm3, and the flow rate is calculated according to the rated demand of the unit evaporator. △T is the temperature difference in and out of the ice machine, P is the cooling capacity of the unit, and t is the unit time. Excuse me: 1. Can the cooling capacity of the unit be calculated according to the above formula? 2. If not, how should the actual cooling capacity of the unit be calculated? (A rough calculation is enough) 3. Looking at the shape and process of the existing unit, is there any room for improvement?
The temperature difference between the inlet and outlet water is small, which affects the cooling efficiency of the unit.
Is it feasible to calculate the cooling capacity of such a computer unit?
There is nothing wrong with the calculation method. This is how I calculate it. As for the cooling capacity that is obviously lower than the designed capacity, it is related to many factors. For new units with -15℃, a COP of 2.6 or above is considered normal. For old units, at least 2.3-2.4 is considered normal. For other things, you have to find the reasons! The superheat degree is generally about 14°C higher than the evaporation temperature, and the evaporation temperature is 5-7°C lower than the chilled water outlet temperature, which is normal.